Many surgical or endoscopic applications require the insertion of an implant into an incision in a patient's soft tissue. For example, such implants can be used to add bulk to a target tissue, thereby reinforcing the target tissue area. These procedures are often referred to as “bulking” procedures, and are frequently used in treating urological diseases, including urinary incontinence and vesicourethral reflux disease. “Bulking” procedures are also often used to treat Gastroesophageal Reflux Disease (hereinafter “GERD”). GERD is a form of dyspepsia that afflicts approximately 40% of adults in the United States. More specifically, GERD is a pathophysiologic condition of the esophagus in which gastric fluids escape from the stomach and travel into the esophagus. The symptoms of GERD can include heartburn, regurgitation of gastric contents, or dysphagia, which is a difficulty in swallowing or moving swallowed material into the stomach. GERD often results from, among other things, transient lower esophageal sphincter (hereinafter “LES”) relaxations and decreased LES resting tone.
One endoscopic procedure used to treat GERD involves transmurally inserting one or more implants into preformed incisions in the LES, and particularly into the submucosal tissue layer, as described in U.S. Pat. No. 6,098,629 to Johnson et al., which is fully incorporated herein by reference. In general, the implants effectively treat GERD by increasing the mass of the LES, thus improving the LES resting tone. The procedure involves first endoscopically identifying an insertion site to access the submucosa adjacent the LES. The layer of mucosa that covers the submucosa is then pierced by a sharp dissection tool. Next, a pouch sized to receive the prosthesis is created in the submucosa. The pouch can be created by liquid infusion (i.e., by forming a blister) or by blunt dissection using a blunt tool. Once the pouch is created, the implant is inserted into the pouch. The implant is typically inserted by a grasper, a clamshell deployment device, or another similar insertion tool. After insertion, the mucosal opening is closed by using an appropriate conventional closing technique.
Soft tissue implants can also be used for brachytherapy. Brachytherapy involves inserting a radioactive implant directly into or adjacent a tumor to effect remission of the tumor. Similarly, soft tissue implants can be used to deliver various drugs to a target location. That is, once an implant impregnated or coated with a drug is implanted in a patient's soft tissue, the implant releases the drug into the patient.
However, presently available procedures for inserting an implant have several significant drawbacks, including implant migration. Implants migrate when, for example, the pouch created to accommodate the implant is too large for the implant. In this situation, the implant can be displaced from its target position into a less ideal position. In more serious cases, implant migration renders the implant entirely ineffective, thus requiring follow-up or additional medical procedures.
Another drawback is the size of presently available implants. Often times a single implant is simply too small to achieve the desired bulk in the target area. Thus, the insertion of multiple implants in the target area is often required. Delivering multiple implants, however, can require that a physician reinsert the delivery tool into a target tissue for each implant, thus increasing the time required for the procedure and causing unnecessary trauma.
Presently available procedures for transmurally inserting an implant, for example, into the LES, have several additional drawbacks. First, creating a pouch for the implant typically causes excessive trauma to the surrounding tissues, especially if a blunt tool is used to create the pouch. Another drawback is that insertion of an implant into the target tissue can be difficult because the implant can catch or snag on the edges of the mucosal incision. Moreover, implants can be difficult to deliver into a target tissue along a desired trajectory and in a desired spatial orientation.